An efficient computing strategy for prediction in mixed linear models

After estimation of effects from a linear mixed model, it is often useful to form predicted values for certain factor/variate combinations. This process has been well-defined for linear models, but the introduction of random effects means that a decision has to be made about the inclusion or exclusion of random model terms from the predictions, including the residual error. For spatially correlated data, kriging then becomes prediction from the fitted model. In many cases, the size of the matrices required to calculate predictions and their covariance matrix directly can be prohibitive. An efficient computational strategy for calculating predictions and their standard errors is given, which includes the ability to detect the invariance of predictions to the parameterisation used in the model

A demonstration of 'broken' visual space

It has long been assumed that there is a distorted mapping between real and ‘perceived’ space, based on demonstrations of systematic errors in judgements of slant, curvature, direction and separation. Here, we have applied a direct test to the notion of a coherent visual space. In an immersive virtual environment, participants judged the relative distance of two squares displayed in separate intervals. On some trials, the virtual scene expanded by a factor of four between intervals although, in line with recent results, participants did not report any noticeable change in the scene. We found that there was no consistent depth ordering of objects that can explain the distance matches participants made in this environment (e.g. A > B > D yet also A < C < D) and hence no single one-to-one mapping between participants’ perceived space and any real 3D environment. Instead, factors that affect pairwise comparisons of distances dictate participants’ performance. These data contradict, more directly than previous experiments, the idea that the visual system builds and uses a coherent 3D internal representation of a scene

GI Bleeding in the Elderly

Purpose: To determine the risk factors contributing to and etiologies of gastrointestinal bleeding in an elderly patient population seen by Southwest Gastroenterology (SWGA) providers. Methods: This study reviews charts of patients with GI bleeding from documented sources between 1/1999 and 3/2006. The cases are gathered retrospectively from the clinical records of SWGA, a 12-person private, single specialty gastroenterology group serving community hospitals. Etiology and risk factors for GI hemorrhages are recorded in an elderly population, defined as patients age 55 and older. Results: GI hemorrhages are identified in 105 patients. The majority (83, 79%) of hemorrhages are upper GI bleeds (UGIB) comparing to 22 (21%) lower GI bleeds (LGIB). In the UGIB group, the most common etiology of bleed is gastric ulcer (29%). We also found 72% of UGIB patients on prescribed anticoagulation medications, including anti-platelet agents or non-steroidal anti-inflammatory drugs (NSAIDs). 20% of these patients are also positive for H. Pylori. Thirty patients in the UGIB group smoke or consume alcohol heavily (consuming more than 3 drinks per day for men and two drinks per day for women) while 2 patients smoke or consume alcohol in the LGIB group. Previous bleeds are common in both groups with 39 (41%) in UGIB and 9 (47%) in LGIB. Co-morbidity is the most common risk factor with 20 (91%) in LGIB and 73 (88%) in UGIB. In the peptic ulcer disease (PUD) bleeds, the majority (77%) are taking NSAIDs, while in the non-PUD bleeds, only 38% are currently on NSAIDs. Overall, there are 2 mortalities resulting from cardiovascular complications of GI bleeding. Conclusion: The etiologies of GI bleeds in this population are comparable to other studies in the literature. The ratio of UGIB to LGIB in this elderly population is also similar to that reported in the literature. The risk factors shown to be most correlated to bleeding are co-morbidities, previous episodes of bleeding, anticoagulation, NSAID use, smoking and alcohol use. NSAID use is significant in PUD bleed patients. This study reinforces that increased knowledge of etiology, incidence and contributing factors of GI bleeding are necessary for physicians to efficiently treat GI bleeds in the elderly population

UNIVERSAL APPROACH TO THE PREVENTION OF THE SYNDROME OF PATHOLOGICAL PREGNANCY

Aim - the purpose of the study is the development of a method for prevention of pathological pregnancy syndrome from the perspective of integral genesis, determined by morphological and functional abnormalities in the fetoplacental system, assessing the effectiveness of methodological standards of evidence-based medicine. Materials and methods. Prospective study of 435 women with high risk of decompensation of placental insufficiency was conducted. Depending on the method of prevention of gestational complications 4 groups were formed: 1st group included 145 pregnant women, who were prescribed dydrogesterone on the 6-20 weeks of gestation, and starting with the 21st week - highly-purified diosmin 600 mg as vasoprotective; in the 2nd group 118 women received a course of preventive treatment with low doses of acetylsalicylic acid; 3rd group included 102 patients who underwent a course of preventive monotherapy with magnesium; 4th group comprised 70 pregnant women who refused preventive treatment. A control group encompassed 30 healthy pregnant women. Dynamic survey included definition of markers of endothelial and hemostasiological dysfunction, vascular-platelet dysfunction elements, apoptosis, inflammatory response, total reactive capacity of the organism, magnesium and carbon dioxide concentrations; a hystostereometric study of placenta was conducted. Standards of evidence-based medicine were applied for the objectification of the effectiveness of the developed method. Results. Method of preventing great obstetric syndromes by successive appointment of progestogen dydrogesterone on the early stage of pregnancy followed by vasoprotective diosmin 600 mg in the 2nd half of pregnancy showed high efficiency (NNT 1.4 (95% CI 1.1 -1.7); OSH 5.3 (95% CI 4.7 -5.8), namely reducing pre-eclampsia by 93%, placental insufficiency with intrauterine growth restriction and/or chronic fetal hypoxia - 95%, preterm birth - 86%, and no premature abruption of normally situated placenta, severe forms of pre-eclampsia and placental insufficiency. Higher clinical effectiveness of the proposed method of prophylaxis of pathological pregnancy syndrome, compared to the use of low-dose acetylsalicylic acid and preparation of magnesium, can be explained by the normalizing effect of dydrogesterone and highly-purified diosmin 600 mg on the immune and biochemical homeostasis, apoptosis and angiogenesis, activation of endothelial and hemostasiological system, adaptive compensatory reactions in the placenta. Conclusion. The method of choice for the prevention of pathological pregnancy syndrome at high risk of fetoplacental system decompensation is the application of progestogen dydrogesterone and vasoprotective diosmin according to the developed method. The study revealed the potential of targeted selection of preventive methods depending on special needs of pregnant women

STRATIFICATION OF PREGNANT WOMEN AT EARLY GESTATIONAL AGES BY MEANS OF OBJECTIVATION OF "PHYSIOLOGICAL ALTERATION" FACTORS, MECHANISMS OF GESTATIONAL ADAPTATION AND FETOPLACENTAL DYSFUNCTION

Aim - allocation of clinical and pathogenetic variants of early gestosis in pregnant women based on clinical manifestations and markers of leading pathogenetic syndromes of gestational maladjustment. Materials and methods. 45 healthy pregnant women and 160 pregnant women with early morning sickness of varying severity were examined in the 1st trimester of gestation. The comparison group consisted of 33 healthy non-pregnant women. The survey included assessment of clinical symptoms, identification of the markers of inflammatory response, energy balance of reproductive system, functional activity of the endometrium, vascular endothelial and hemostatic disorders, and blood biochemical indices. Results. The study enabled quantitative objectivation of the factors of “physiological damage” and “the mechanisms of gestational adaptation” during physiological gestation, defining fetoplacental dysfunction as the key link of maladjustment in early pregnancy. The prevalence of pathogenetic mechanisms of the formation of early pregnancy toxicosis determined the allocation of 4 clinical-pathogenetic variants of the course of this complication of gestation. Conclusion. Differentiated approach to clinical and laboratory manifestations of early gestosis in pregnant women, taking into account the variants of the clinical course of this complication and severity assessment, enables targeted therapy and predicting the risk of development of severe forms and late obstetric complications, reduces the risk of adverse perinatal outcomes

Mesenchymal stem cells secretome-induced axonal outgrowth is mediated by BDNF

Mesenchymal stem cells (MSCs) have been used for cell-based therapies in regenerative medicine, with increasing importance in central and peripheral nervous system repair. However, MSCs grafting present disadvantages, such as, a high number of cells required for transplantation and low survival rate when transplanted into the central nervous system (CNS). In line with this, MSCs secretome which present on its composition a wide range of molecules (neurotrophins, cytokines) and microvesicles, can be a solution to surpass these problems. However, the effect of MSCs secretome in axonal elongation is poorly understood. In this study, we demonstrate that application of MSCs secretome to both rat cortical and hippocampal neurons induces an increase in axonal length. In addition, we show that this growth effect is axonal intrinsic with no contribution from the cell body. To further understand which are the molecules required for secretome-induced axonal outgrowth effect, we depleted brain-derived neurotrophic factor (BDNF) from the secretome. Our results show that in the absence of BDNF, secretome-induced axonal elongation effect is lost and that axons present a reduced axonal growth rate. Altogether, our results demonstrate that MSCs secretome is able to promote axonal outgrowth in CNS neurons and this effect is mediated by BDNF.European Regional Development Fund (ERDF), through the Centro 2020 Regional Operational Programme under project CENTRO-01–0145-FEDER-000008:BrainHealth 2020, and through the COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation and Portuguese national funds via FCT – Fundação para a Ciência e a Tecnologia, I.P., under projects PTDC/SAU-NEU/104100/2008, EXPL/NEU-NMC/0541/2012 and UID/NEU/04539/2013. This work was also funded by Marie Curie Actions - International reintegration grant #249288, 7th Framework programme, EU. Partially funded by Prémios Santa Casa Neurociências - Prize Melo e Castro for Spinal Cord Injury Research; Portuguese Foundation for Science and Technology (IF Development Grant to A.J.S.); NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme; by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by national funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038. The authors would also like to acknowledge Prof. J.E. Davies from the Institute of Biomaterials and Biomedical Engineering at the University of Toronto, Canada, for kindly providing some of the HUCPVCs lots used in the present workinfo:eu-repo/semantics/publishedVersio

Being Barbie: The Size of One’s Own Body Determines the Perceived Size of the World

A classical question in philosophy and psychology is if the sense of one's body influences how one visually perceives the world. Several theoreticians have suggested that our own body serves as a fundamental reference in visual perception of sizes and distances, although compelling experimental evidence for this hypothesis is lacking. In contrast, modern textbooks typically explain the perception of object size and distance by the combination of information from different visual cues. Here, we describe full body illusions in which subjects experience the ownership of a doll's body (80 cm or 30 cm) and a giant's body (400 cm) and use these as tools to demonstrate that the size of one's sensed own body directly influences the perception of object size and distance. These effects were quantified in ten separate experiments with complementary verbal, questionnaire, manual, walking, and physiological measures. When participants experienced the tiny body as their own, they perceived objects to be larger and farther away, and when they experienced the large-body illusion, they perceived objects to be smaller and nearer. Importantly, despite identical retinal input, this “body size effect” was greater when the participants experienced a sense of ownership of the artificial bodies compared to a control condition in which ownership was disrupted. These findings are fundamentally important as they suggest a causal relationship between the representations of body space and external space. Thus, our own body size affects how we perceive the world